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21 * @file ats/ats_api_scheduling.c
22 * @brief automatic transport selection and outbound bandwidth determination
23 * @author Christian Grothoff
24 * @author Matthias Wachs
27 * - we could avoid a linear scan over the
28 * active addresses in some cases, so if
29 * there is need, we can still optimize here
30 * - we might want to split off the logic to
31 * determine LAN vs. WAN, as it has nothing
32 * to do with accessing the ATS service.
35 #include "gnunet_ats_service.h"
39 * How frequently do we scan the interfaces for changes to the addresses?
41 #define INTERFACE_PROCESSING_INTERVAL GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MINUTES, 2)
43 #define LOG(kind,...) GNUNET_log_from(kind, "ats-scheduling-api", __VA_ARGS__)
46 * Session ID we use if there is no session / slot.
52 * Information we track per address, incoming or outgoing. It also
53 * doesn't matter if we have a session, any address that ATS is
54 * allowed to suggest right now should be tracked.
56 struct GNUNET_ATS_AddressRecord
60 * Scheduling handle this address record belongs to.
62 struct GNUNET_ATS_SchedulingHandle *sh;
67 struct GNUNET_HELLO_Address *address;
70 * Session handle. NULL if we have an address but no
71 * active session for this address.
73 struct Session *session;
76 * Performance data about the address.
78 struct GNUNET_ATS_PropertiesNBO properties;
81 * Which slot (index) in the session array does
82 * this record correspond to? FIXME:
83 * FIXME: a linear search on this is really crappy!
84 * Maybe switch to a 64-bit global counter and be
85 * done with it? Or does that then cause too much
86 * trouble on the ATS-service side?
91 * We're about to destroy this address record, just ATS does
92 * not know this yet. Once ATS confirms its destruction,
100 * Handle to the ATS subsystem for bandwidth/transport scheduling information.
102 struct GNUNET_ATS_SchedulingHandle
108 const struct GNUNET_CONFIGURATION_Handle *cfg;
111 * Callback to invoke on suggestions.
113 GNUNET_ATS_AddressSuggestionCallback suggest_cb;
116 * Closure for @e suggest_cb.
118 void *suggest_cb_cls;
121 * Connection to ATS service.
123 struct GNUNET_CLIENT_Connection *client;
126 * Message queue for sending requests to the ATS service.
128 struct GNUNET_MQ_Handle *mq;
131 * Array of session objects (we need to translate them to numbers and back
132 * for the protocol; the offset in the array is the session number on the
133 * network). Index 0 is always NULL and reserved to represent the NULL pointer.
134 * Unused entries are also NULL.
136 struct GNUNET_ATS_AddressRecord **session_array;
139 * Task to trigger reconnect.
141 struct GNUNET_SCHEDULER_Task *task;
144 * Reconnect backoff delay.
146 struct GNUNET_TIME_Relative backoff;
149 * Size of the @e session_array.
151 unsigned int session_array_size;
157 * Re-establish the connection to the ATS service.
159 * @param sh handle to use to re-connect.
162 reconnect (struct GNUNET_ATS_SchedulingHandle *sh);
166 * Re-establish the connection to the ATS service.
168 * @param cls handle to use to re-connect.
169 * @param tc scheduler context
172 reconnect_task (void *cls,
173 const struct GNUNET_SCHEDULER_TaskContext *tc)
175 struct GNUNET_ATS_SchedulingHandle *sh = cls;
183 * Disconnect from ATS and then reconnect.
185 * @param sh our handle
188 force_reconnect (struct GNUNET_ATS_SchedulingHandle *sh)
192 GNUNET_MQ_destroy (sh->mq);
195 if (NULL != sh->client)
197 GNUNET_CLIENT_disconnect (sh->client);
200 sh->suggest_cb (sh->suggest_cb_cls,
202 GNUNET_BANDWIDTH_ZERO,
203 GNUNET_BANDWIDTH_ZERO);
204 sh->backoff = GNUNET_TIME_STD_BACKOFF (sh->backoff);
205 sh->task = GNUNET_SCHEDULER_add_delayed (sh->backoff,
212 * Find the session object corresponding to the given session ID.
214 * @param sh our handle
215 * @param session_id current session ID
216 * @param peer peer the session belongs to
217 * @return the session object (or NULL)
219 static struct GNUNET_ATS_AddressRecord *
220 find_session (struct GNUNET_ATS_SchedulingHandle *sh,
222 const struct GNUNET_PeerIdentity *peer)
224 struct GNUNET_ATS_AddressRecord *ar;
226 if (session_id >= sh->session_array_size)
233 ar = sh->session_array[session_id];
239 if (NULL == ar->address)
241 /* address was destroyed in the meantime, this can happen
242 as we communicate asynchronously with the ATS service. */
245 if (0 != memcmp (peer,
247 sizeof (struct GNUNET_PeerIdentity)))
250 force_reconnect (sh);
258 * Get an available session ID.
260 * @param sh our handle
261 * @return an unused slot, but never NOT_FOUND (0)
264 find_empty_session_slot (struct GNUNET_ATS_SchedulingHandle *sh)
270 while ( ( (NOT_FOUND == off) ||
271 (NULL != sh->session_array[off % sh->session_array_size]) ) &&
272 (i < sh->session_array_size) )
277 if ( (NOT_FOUND != off % sh->session_array_size) &&
278 (NULL == sh->session_array[off % sh->session_array_size]) )
280 i = sh->session_array_size;
281 GNUNET_array_grow (sh->session_array,
282 sh->session_array_size,
283 sh->session_array_size * 2);
289 * Get the ID for the given session object.
291 * @param sh our handle
292 * @param session session object
293 * @param address the address we are looking for
294 * @return the session id or NOT_FOUND for error
297 find_session_id (struct GNUNET_ATS_SchedulingHandle *sh,
298 struct Session *session,
299 const struct GNUNET_HELLO_Address *address)
308 for (i = 1; i < sh->session_array_size; i++)
309 if ( (NULL != sh->session_array[i]) &&
310 (GNUNET_NO == sh->session_array[i]->in_destroy) &&
311 ( (session == sh->session_array[i]->session) ||
312 (NULL == sh->session_array[i]->session) ) &&
313 (0 == GNUNET_HELLO_address_cmp (address,
314 sh->session_array[i]->address)) )
321 * Release the session slot from the session table (ATS service is
322 * also done using it).
324 * @param sh our handle
325 * @param session_id identifies session that is no longer valid
328 release_session (struct GNUNET_ATS_SchedulingHandle *sh,
331 struct GNUNET_ATS_AddressRecord *ar;
333 if (NOT_FOUND == session_id)
335 if (session_id >= sh->session_array_size)
338 force_reconnect (sh);
341 /* this slot should have been removed from remove_session before */
342 ar = sh->session_array[session_id];
343 if (NULL != ar->session)
346 force_reconnect (sh);
349 GNUNET_HELLO_address_free (ar->address);
351 sh->session_array[session_id] = NULL;
356 * Type of a function to call when we receive a session release
357 * message from the service.
359 * @param cls the `struct GNUNET_ATS_SchedulingHandle`
360 * @param msg message received, NULL on timeout or fatal error
363 process_ats_session_release_message (void *cls,
364 const struct GNUNET_MessageHeader *msg)
366 struct GNUNET_ATS_SchedulingHandle *sh = cls;
367 const struct SessionReleaseMessage *srm;
369 srm = (const struct SessionReleaseMessage *) msg;
370 /* Note: peer field in srm not necessary right now,
371 but might be good to have in the future */
373 ntohl (srm->session_id));
378 * Type of a function to call when we receive a address suggestion
379 * message from the service.
381 * @param cls the `struct GNUNET_ATS_SchedulingHandle`
382 * @param msg message received, NULL on timeout or fatal error
385 process_ats_address_suggestion_message (void *cls,
386 const struct GNUNET_MessageHeader *msg)
388 struct GNUNET_ATS_SchedulingHandle *sh = cls;
389 const struct AddressSuggestionMessage *m;
390 struct GNUNET_ATS_AddressRecord *ar;
393 m = (const struct AddressSuggestionMessage *) msg;
394 session_id = ntohl (m->session_id);
398 force_reconnect (sh);
401 ar = find_session (sh,
407 force_reconnect (sh);
410 if (NULL == sh->suggest_cb)
412 if (GNUNET_YES == ar->in_destroy)
414 /* ignore suggestion, as this address is dying, unless BW is 0,
415 in that case signal 'disconnect' via BW 0 */
416 if ( (0 == ntohl (m->bandwidth_out.value__)) &&
417 (0 == ntohl (m->bandwidth_in.value__)) )
419 LOG (GNUNET_ERROR_TYPE_DEBUG,
420 "ATS suggests disconnect from peer `%s' with BW %u/%u\n",
421 GNUNET_i2s (&ar->address->peer),
422 (unsigned int) ntohl (m->bandwidth_out.value__),
423 (unsigned int) ntohl (m->bandwidth_in.value__));
424 sh->suggest_cb (sh->suggest_cb_cls,
433 if ( (NULL == ar->session) &&
434 (GNUNET_HELLO_address_check_option (ar->address,
435 GNUNET_HELLO_ADDRESS_INFO_INBOUND)) )
440 sh->backoff = GNUNET_TIME_UNIT_ZERO;
441 LOG (GNUNET_ERROR_TYPE_DEBUG,
442 "ATS suggests address slot %u for peer `%s' using plugin %s\n",
444 GNUNET_i2s (&ar->address->peer),
445 ar->address->transport_name);
446 sh->suggest_cb (sh->suggest_cb_cls,
456 * We encountered an error handling the MQ to the
457 * ATS service. Reconnect.
459 * @param cls the `struct GNUNET_ATS_SchedulingHandle`
460 * @param error details about the error
463 error_handler (void *cls,
464 enum GNUNET_MQ_Error error)
466 struct GNUNET_ATS_SchedulingHandle *sh = cls;
468 LOG (GNUNET_ERROR_TYPE_ERROR,
469 "ATS connection died (code %d), reconnecting\n",
471 force_reconnect (sh);
476 * Generate and transmit the `struct AddressAddMessage` for the given
479 * @param sh the scheduling handle to use for transmission
480 * @param ar the address to inform the ATS service about
483 send_add_address_message (struct GNUNET_ATS_SchedulingHandle *sh,
484 const struct GNUNET_ATS_AddressRecord *ar)
486 struct GNUNET_MQ_Envelope *ev;
487 struct AddressAddMessage *m;
493 return; /* disconnected, skip for now */
494 namelen = strlen (ar->address->transport_name) + 1;
495 msize = ar->address->address_length + namelen;
496 ev = GNUNET_MQ_msg_extra (m, msize, GNUNET_MESSAGE_TYPE_ATS_ADDRESS_ADD);
497 m->peer = ar->address->peer;
498 m->address_length = htons (ar->address->address_length);
499 m->address_local_info = htonl ((uint32_t) ar->address->local_info);
500 m->plugin_name_length = htons (namelen);
501 m->session_id = htonl (ar->slot);
502 m->properties = ar->properties;
504 LOG (GNUNET_ERROR_TYPE_DEBUG,
505 "Adding address for peer `%s', plugin `%s', session %p slot %u\n",
506 GNUNET_i2s (&ar->address->peer),
507 ar->address->transport_name,
512 ar->address->address,
513 ar->address->address_length);
514 if (NULL != ar->address->transport_name)
515 memcpy (&pm[ar->address->address_length],
516 ar->address->transport_name,
518 GNUNET_MQ_send (sh->mq, ev);
523 * Re-establish the connection to the ATS service.
525 * @param sh handle to use to re-connect.
528 reconnect (struct GNUNET_ATS_SchedulingHandle *sh)
530 static const struct GNUNET_MQ_MessageHandler handlers[] =
531 { { &process_ats_session_release_message,
532 GNUNET_MESSAGE_TYPE_ATS_SESSION_RELEASE,
533 sizeof (struct SessionReleaseMessage) },
534 { &process_ats_address_suggestion_message,
535 GNUNET_MESSAGE_TYPE_ATS_ADDRESS_SUGGESTION,
536 sizeof (struct AddressSuggestionMessage) },
538 struct GNUNET_MQ_Envelope *ev;
539 struct ClientStartMessage *init;
541 struct GNUNET_ATS_AddressRecord *ar;
543 GNUNET_assert (NULL == sh->client);
544 sh->client = GNUNET_CLIENT_connect ("ats",
546 if (NULL == sh->client)
549 force_reconnect (sh);
552 sh->mq = GNUNET_MQ_queue_for_connection_client (sh->client,
556 ev = GNUNET_MQ_msg (init,
557 GNUNET_MESSAGE_TYPE_ATS_START);
558 init->start_flag = htonl (START_FLAG_SCHEDULING);
559 GNUNET_MQ_send (sh->mq, ev);
562 for (i=0;i<sh->session_array_size;i++)
564 ar = sh->session_array[i];
567 send_add_address_message (sh, ar);
575 * Initialize the ATS subsystem.
577 * @param cfg configuration to use
578 * @param suggest_cb notification to call whenever the suggestation changed
579 * @param suggest_cb_cls closure for @a suggest_cb
580 * @return ats context
582 struct GNUNET_ATS_SchedulingHandle *
583 GNUNET_ATS_scheduling_init (const struct GNUNET_CONFIGURATION_Handle *cfg,
584 GNUNET_ATS_AddressSuggestionCallback suggest_cb,
585 void *suggest_cb_cls)
587 struct GNUNET_ATS_SchedulingHandle *sh;
589 sh = GNUNET_new (struct GNUNET_ATS_SchedulingHandle);
591 sh->suggest_cb = suggest_cb;
592 sh->suggest_cb_cls = suggest_cb_cls;
593 GNUNET_array_grow (sh->session_array,
594 sh->session_array_size,
602 * Client is done with ATS scheduling, release resources.
604 * @param sh handle to release
607 GNUNET_ATS_scheduling_done (struct GNUNET_ATS_SchedulingHandle *sh)
609 struct GNUNET_ATS_AddressRecord *ar;
614 GNUNET_MQ_destroy (sh->mq);
617 if (NULL != sh->client)
619 GNUNET_CLIENT_disconnect (sh->client);
622 if (NULL != sh->task)
624 GNUNET_SCHEDULER_cancel (sh->task);
627 for (i=0;i<sh->session_array_size;i++)
629 if (NULL != (ar = sh->session_array[i]))
631 GNUNET_HELLO_address_free (ar->address);
633 sh->session_array[i] = NULL;
636 GNUNET_array_grow (sh->session_array,
637 sh->session_array_size,
644 * We have a new address ATS should know. Addresses have to be added
645 * with this function before they can be: updated, set in use and
649 * @param address the address
650 * @param session session handle, can be NULL
651 * @param prop performance data for the address
652 * @return handle to the address representation inside ATS, NULL
653 * on error (i.e. ATS knows this exact address already)
655 struct GNUNET_ATS_AddressRecord *
656 GNUNET_ATS_address_add (struct GNUNET_ATS_SchedulingHandle *sh,
657 const struct GNUNET_HELLO_Address *address,
658 struct Session *session,
659 const struct GNUNET_ATS_Properties *prop)
661 struct GNUNET_ATS_AddressRecord *ar;
668 /* we need a valid address */
672 namelen = strlen (address->transport_name) + 1;
673 msize = address->address_length + namelen;
674 if ((msize + sizeof (struct AddressUpdateMessage) >= GNUNET_SERVER_MAX_MESSAGE_SIZE) ||
675 (address->address_length >= GNUNET_SERVER_MAX_MESSAGE_SIZE) ||
676 (namelen >= GNUNET_SERVER_MAX_MESSAGE_SIZE) )
678 /* address too large for us, this should not happen */
688 /* Already existing, nothing todo, but this should not happen */
692 s = find_empty_session_slot (sh);
693 ar = GNUNET_new (struct GNUNET_ATS_AddressRecord);
696 ar->session = session;
697 ar->address = GNUNET_HELLO_address_copy (address);
698 GNUNET_ATS_properties_hton (&ar->properties,
700 sh->session_array[s] = ar;
701 send_add_address_message (sh, ar);
707 * An address was used to initiate a session.
709 * @param ar address record to update information for
710 * @param session session handle
713 GNUNET_ATS_address_add_session (struct GNUNET_ATS_AddressRecord *ar,
714 struct Session *session)
716 GNUNET_break (NULL == ar->session);
717 ar->session = session;
722 * A session was destroyed, disassociate it from the
723 * given address record. If this was an incoming
724 * addess, destroy the address as well.
726 * @param ar address record to update information for
727 * @param session session handle
728 * @return #GNUNET_YES if the @a ar was destroyed because
729 * it was an incoming address,
730 * #GNUNET_NO if the @ar was kept because we can
731 * use it still to establish a new session
734 GNUNET_ATS_address_del_session (struct GNUNET_ATS_AddressRecord *ar,
735 struct Session *session)
737 GNUNET_assert (session == ar->session);
739 if (GNUNET_HELLO_address_check_option (ar->address,
740 GNUNET_HELLO_ADDRESS_INFO_INBOUND))
742 GNUNET_ATS_address_destroy (ar);
750 * We have updated performance statistics for a given address. Note
751 * that this function can be called for addresses that are currently
752 * in use as well as addresses that are valid but not actively in use.
753 * Furthermore, the peer may not even be connected to us right now (in
754 * which case the call may be ignored or the information may be stored
755 * for later use). Update bandwidth assignments.
757 * @param ar address record to update information for
758 * @param prop performance data for the address
761 GNUNET_ATS_address_update (struct GNUNET_ATS_AddressRecord *ar,
762 const struct GNUNET_ATS_Properties *prop)
764 struct GNUNET_ATS_SchedulingHandle *sh = ar->sh;
765 struct GNUNET_MQ_Envelope *ev;
766 struct AddressUpdateMessage *m;
768 LOG (GNUNET_ERROR_TYPE_DEBUG,
769 "Updating address for peer `%s', plugin `%s', session %p slot %u\n",
770 GNUNET_i2s (&ar->address->peer),
771 ar->address->transport_name,
774 GNUNET_ATS_properties_hton (&ar->properties,
777 return; /* disconnected, skip for now */
778 ev = GNUNET_MQ_msg (m, GNUNET_MESSAGE_TYPE_ATS_ADDRESS_UPDATE);
779 m->session_id = htonl (ar->slot);
780 m->peer = ar->address->peer;
781 m->properties = ar->properties;
782 GNUNET_MQ_send (sh->mq,
789 * An address got destroyed, stop using it as a valid address.
791 * @param ar address to destroy
794 GNUNET_ATS_address_destroy (struct GNUNET_ATS_AddressRecord *ar)
796 struct GNUNET_ATS_SchedulingHandle *sh = ar->sh;
797 struct GNUNET_MQ_Envelope *ev;
798 struct AddressDestroyedMessage *m;
800 LOG (GNUNET_ERROR_TYPE_DEBUG,
801 "Deleting address for peer `%s', plugin `%s', slot %u session %p\n",
802 GNUNET_i2s (&ar->address->peer),
803 ar->address->transport_name,
806 GNUNET_break (NULL == ar->session);
808 ar->in_destroy = GNUNET_YES;
811 ev = GNUNET_MQ_msg (m, GNUNET_MESSAGE_TYPE_ATS_ADDRESS_DESTROYED);
812 m->session_id = htonl (ar->slot);
813 m->peer = ar->address->peer;
814 GNUNET_MQ_send (sh->mq, ev);
818 /* end of ats_api_scheduling.c */